Activation keys, as implied by the name, are used to activate something. For example, a piece of computer software may be installed on a computer, but the software may be inoperative until it is activated using an activation key. The vendor of the software may only provide the activation key to those who have been authorized to use the software. Activation keys can also be used to verify that a person signing up for a service is actually authorized to do so. For example, a person may sign up with the local power company to review their home power bill online through the power company's website. Prior to allowing access, the power company may send, through the US Mail, a letter containing an activation key, to the subscribers home address. If the subscriber is able to enter the activation key, access will be granted. This scheme allows the power company to infer with some degree of confidence that the subscriber actually lives at the address, because he has access to mail sent to the address.
Activation keys may also be used to restrict offers to a selected group. For example, a merchant may send his best customers an advertisement that includes a promotion code which will entitle the customers to a discount on a purchase. The promotion code is an activation key that activates the discount. The merchant may not wish to offer the discount to every customer, so through use of an activation key, the offer can be limited to only those who are selected to participate in the promotion.
Activation keys are useful in verifying that an individual is authorized to use the product or service that is being activated. Activation keys can also be used to confirm attributes, such as an address, of persons signing up for services. The distribution of an activation key can also be limited to selected individuals, thus providing a way of limiting who can access a product or service.